The Reaserch On Integrated De-Multiplexing Receiver For Optical Communications

WDM (Wavelength-Division-Multiplexing) is one promising approach that can be used to exploit the huge bandwidth of optical fiber which is also capable of providing high capacity, flexible and reliable telecommunication networks. Wavelength demultiplexer (DMUX) and photodetector (PD) are key devices for wavelength demultiplexing and end-user receiving in WDM system, respectively. The performance of DMUX and PD is rather important to the WDM system. In this dissertation, integrated demultiplexing receiver with tunable characteristic as well as flat-top and steep-edge spectral response is studied in detail, including structure design、performance simulation and optimization as well as experiment verification. The main contents and innovations are listed as follows:1、A novel integrated demultiplexing receiver with flat-top and steep-edge spectral response is designed by using step shaped structure. Theoretical analyses indicate that the quantum efficiency can reach about 50.2% in the flat-top passband. The 0.5dB and 3dB bandwidth is 0.26nm and 0.4nm, respectively. In addition, different kinds of step shaped structure with flat-top and steep-edge spectral response are discussed and compared.2. Integrated demultiplexing receiver whose wavelength and FWHM (full width at half maximum) are independently tunable is designed with a movable mirror actuated by electrostatic forces. By displacing the movable mirror, the Fabry-Perot cavity length is changed thus the resonant wavelength and FWHM can be tuned. The simulation results indicate that a large wavelength tuning range can be achieved. Quantum efficiency of 93.9% at the resonant wavelength of 1.55μm and a FWHM of 0.38nm are obtained. When the thickness of the F-P cavity varies an integer multiple of the half central wavelength, the FWHM of the transmitted spectrum of the F-P filter can be tuned from 0.38nm to 0.92nm.3、An integrated vertical-cavity semiconductor optical amplifiers (VCSOAs) with PIN PD is designed for the first time. The trade-off between bandwidth and peak gain as well as the influence of mirror reflectivity and carrier density on the property of VCSOA are discussed for the case of reflection and transmission mode operation of the VCSOA. On the basis of the study mentioned above, the transmission mode operation of VCSOA integrated with PIN PD is designed. The quantum efficiency of the designed device can reach higher than 100%with a thin absorption layer. In addition, influence of reflectivities of the bottom and top mirrors as well as the carrier density on the integrated device are also investigated.4、1550nm PIN PD integrated with step-type F-P cavity structure is designed and realized. The integrated device is fabricated by wet etching and regrowth. The spectral response and the frequency response are measured. The device has a peak quantum efficiency of 25%around 1549nm and a FWHM of 4.2nm. The 3dB bandwidth of the device is 17GHz。...